We randomly assigned 4589 healthy nulliparous women who were 13 to 21 weeks pregnant to receive daily treatment with either 2g of elemental calcium or placebo for the remainder of their pregnancies. Surveillance for preeclampsia was conducted by personnel unaware of treatment-group assignments using standardized measurements of blood pressure and urinary protein excretion at uniformly scheduled prenatal visits, protocols for monitoring these measurements during the hospitalization for delivery, and reviews of medical records of unscheduled outpatient visits and all hospitalizations. Calcium supplementation did not significantly reduce the incidence or severity of preeclampsia or delay its onset. Additional analyses utilizing the study database and specimen repository are being performed. During FY03, the following papers were published: one on abortion, paternity, and risk of preeclampsia in nulliparous women. Manuscripts on glucose tolerance, gestational diabetes, and smoking; pregnancy outcomes in smokers who develop preeclampsia; cell-free fetal DNA and C-reactive protein in preeclampsia; and pro- and anti-angiogenic factors in preeclampsia have been submitted for publication. Other studies are underway on urinary insulin in preeclampsia and gestational hypertension and on angiogenesis in preeclampsia.